Video-assisted thoracoscopy system guidance in linear radiofrequency ablation

The transcatheter creation of linear endocardial lesions in the atria has been attempted to restore sinus rhythm in patients with atrial fibrillation (AF). However, due to fluoroscopic limitations, there are a number of technical difficulties involved with using this procedure, which include determining the ablation site, orienting the catheter tip, and confirming tip-tissue contact. The present study was performed to assess the feasibility of employing a transthoracic approach to linear radiofrequency ablation using a video-assisted thoracoscopy system (VATS) to anatomically guide the experimental setting in beating swine hearts. AF was induced pharmacologically by aconitine solution. Epicardial radiofrequency linear ablation of the right atrium was conducted under VATS monitoring using an ablation catheter that was inserted and manipulated through trocar ports. The ablation energy setting was 80 degrees C with 30s duration per ablation. The thoracoscopic visual field for transthoracic ablation was adequate, and the ablation catheter was positioned and anchored safely on the atrial epicardium. The restoration of sinus rhythm was confirmed in the limb lead and atrial electrograms, and transmural heat degeneration was confirmed by postmortem histological examination in all specimens. Our results suggest the potential usefulness of VATS for providing adequate anatomical guidance in epicardial linear radiofrequency ablation.